Emma Sherratt

Emma Sherratt
University of Adelaide · Faculty of Sciences

Ph.D. Animal Biology

About

109
Publications
45,218
Reads
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2,406
Citations
Additional affiliations
January 2020 - present
University of Adelaide
Position
  • Fellow
Description
  • Research fellow on an Australian Research Council mid-career fellowship
April 2019 - December 2019
University of Adelaide
Position
  • Lecturer
Description
  • Unit coordinator and instructor: Undergraduate student courses (L1-L3). Principles & Practices of Research (Advanced) I, II, III (SCIENCE 1300, 2300, 3100)
April 2019 - December 2019
University of Adelaide
Position
  • Lecturer
Description
  • Fixed-term teaching-research position, coordinating the BSc. Advanced “Principles & Practices of Research” L1-L3 courses (SCIENCE 1300, 2300, 3100)
Education
September 2008 - June 2011
The University of Manchester
Field of study
  • Animal Biology
September 2002 - June 2006
The University of Manchester
Field of study
  • Zoology with Industrial Experience

Publications

Publications (109)
Article
Full-text available
Significance An unresolved question in ecology is whether the structure of ecological communities can be stable over very long timescales. Here we describe a wealth of new amber fossils for an ancient radiation of Hispaniolan lizards that, until now, has had a very poor fossil record. These fossils provide an important and previously unavailable pe...
Article
Insights into morphological diversification can be obtained from the ways the species of a clade occupy morphospace. Projecting a phylogeny into morphospace provides estimates of evolutionary trajectories as lineages diversified information that can be used to infer the dynamics of evolutionary processes that produced patterns of morphospace occupa...
Article
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Directional evolution is one of the most compelling evolutionary patterns observed in macroevolution. Yet, despite its importance, detecting such trends in multivariate data remains a challenge. In this study, we evaluate multivariate evolution of shell shape in 93 bivalved scallop species, combining geometric morphometrics and phylogenetic compara...
Article
Developmental changes through an animal's life are generally understood to contribute to the resulting adult morphology. Possible exceptions are species with complex life cycles, where individuals pass through distinct ecological and morphological life stages during their ontogeny, ending with metamorphosis to the adult form. Antagonistic selection...
Article
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In mammalian vertebral columns, locomotive ability is expected to be an evolutionary driver of variation in the number of vertebrae; in species evolved to run fast or have a flexible vertebral column, they generally have limited numerical variation and low occurrence of malformed vertebrae to maintain their running performance. Although this hypoth...
Article
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We studied ontogenetic variation in skull morphology in tiger snakes sampled from mainland South Australia (Coffin Bay), mainland Western Australia (Herdsman Lake), Franklin Island, and Hopkins Island. The snakes from the two islands were selected because of their unusually large absolute body and head size, likely attained as a result of dietary c...
Article
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Nilpena Ediacara National Park (South Australia) preserves over 200 specimens of Tribrachidium heraldicum and 95 specimens of the newly described Tribrachidium gehlingi within the fossiliferous Ediacara Member. We use rotational geometric mor- phometrics to quantify the morphological variation within each species and the differ- ences between the t...
Article
Recent research into the snake vertebral column has highlighted the importance of considering regionalization and its implications for the life history of snakes. Our research delves into the distinctions in vertebral column morphology and regionalization within the snake family Colubridae, comparing arboreal and terrestrial species. Our results pr...
Article
Ecological drivers of variation in the morphology of the lizard tail are understudied despite its important and varied functions in defence, locomotion, balance, climbing, and resource storage. We quantified variation in original tail shape and surface area-to-volume ratio (SA : V) in an Australian gecko clade (Oedura) and tested whether environmen...
Article
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The mammalian cranium (skull without lower jaw) is representative of mammalian diversity and is thus of particular interest to mammalian biologists across disciplines. One widely retrieved pattern accompanying mammalian cranial diversification is referred to as ‘craniofacial evolutionary allometry’ (CREA). This posits that adults of larger species,...
Article
Eoandromeda octobrachiata is a poorly understood Ediacaran organism, with spiral octoradial arms, found in South Australia and South China. The informal Nilpena member of the Rawnsley Quartzite, Flinders Ranges in South Australia preserves more than 200 specimens of Eoandromeda . Here we use the novel application of rotational geometric morphometri...
Article
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Over the last 5 million years, numerous species of Australian stygobiotic (subterranean and aquatic) beetles have evolved underground following independent colonization of aquifers by surface ancestors, providing a set of repeated evolutionary transitions from surface to subterranean life. We used this system as an ‘evolutionary experiment’ to inve...
Article
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Recent studies have found correlations between the shape of snake teeth/fangs and diet. These studies were done at a very broad phylogenetic scale, making it desirable to test if correlations are still detectable at a narrower evolutionary scale, specifically within the family Elapidae. To this end, we studied fang shape in a dense selection of ela...
Article
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The remarkable diversity of ecological niches that birds have evolved to inhabit have resulted in their status as model organisms to study how the same morphological features can adapt to different environments. Not least of these features is the avian foot, which has diversified into a wide range of forms suited to several different ecological fun...
Article
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Among the many catastrophic introductions of exotic species to Australia, the Australian Dung Beetle Project stands apart as a success story. From 1965 dung beetles (Coleoptera: Scarabaeinae) were introduced for biological control purposes, and 23 species survived to become integrated into the environment with apparently little-to-no competition wi...
Article
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Background The shape of the semicircular canals of the inner ear of living squamate reptiles has been used to infer phylogenetic relationships, body size, and life habits. Often these inferences are made without controlling for the effects of the other ones. Here we examine the semicircular canals of 94 species of extant limbed lepidosaurs using th...
Article
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Biological variation is often considered in a scalable hierarchy, e.g., within the individual, within the populations, above the species level. Morphological integration, the concept of covariation among constituent parts of an organism, is also hierarchical; the degree to which these 'modules' covary is a matter of the scale of the study as well a...
Article
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Repeated island colonisation by Australian tiger snakes (Notechis scutatus) has become a model system demonstrating how prey size on islands influences a snake’s body and jaw size. Tiger snakes on islands with large prey have relatively longer jaws compared to their mainland counterparts, due to diet-induced phenotypic plasticity followed by assimi...
Article
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Sea snakes in the Hydrophis-Microcephalophis clade (Elapidae) show exceptional body shape variation along a continuum from similar forebody and hindbody girths, to dramatically reduced girths of the forebody relative to hindbody. The latter is associated with specializations on burrowing prey. This variation underpins high sympatric diversity and s...
Article
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Highly cursorial animals are specialised for fast, sustained running via specific morphological adaptations, notably including changes in limb segment length and mechanical advantage. Members of the order Lagomorpha (hares, rabbits and pikas) vary in cursorial ability; hares are generally highly cursorial, rabbits more frequently saltate, and pikas...
Article
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Studies on the evolution of brain size variation usually focus on large clades encompassing broad phylogenetic groups. This risks introducing ‘noise’ in the results, often obscuring effects that might be detected in less inclusive clades. Here, we focus on a sample of endocranial volumes (endocasts) of 18 species of rabbits and hares (Lagomorpha: L...
Article
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Domestication leads to phenotypic characteristics that have been described to be similar across species. However, this "domestication syndrome" has been subject to debate, related to a lack of evidence for certain characteristics in many species. Here we review diverse literature and provide new data on cranial shape changes due to domestication in...
Article
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Allometry—the study of proportional growth of body parts, and the relationship of body size to an organism’s morphology, physiology and behaviour—is a fundamental influencer of ecological and evolutionary diversity. Allometric studies can focus on scaling across an individual's development (ontogenetic allometry), among individuals at the same deve...
Article
Full-text available
As snakes are limbless, gape-limited predators, their skull is the main feeding structure involved in prey handling, manipulation and feeding. Ontogenetic changes in prey type and size are likely to be associated with distinct morphological changes in the skull during growth. We investigated ontogenetic variation in diet from stomach contents of 16...
Article
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Despite only comprising seven species, extant sea turtles (Cheloniidae and Dermochelyidae) display great ecological diversity, with most species inhabiting a unique dietary niche as adults. This adult diversity is remarkable given that all species share the same dietary niche as juveniles. These ontogenetic shifts in diet, as well as a dramatic inc...
Article
Within-species morphological variation is often observed across spatial and climatic gradients. Understanding this variation is important to conservation planning, as specialised adaptations may influence a population’s persistence following translocation. However, knowing whether local adaptations are prevalent within a species can be challenging...
Preprint
Full-text available
As snakes are limbless, gape-limited predators, their skull is the main feeding structure involved in prey handling, manipulation and feeding. Ontogenetic changes in prey type and size are likely to be associated with distinct morphological changes in the skull during growth. We investigated ontogenetic variation in diet from stomach contents of n...
Article
Full-text available
Due to their global distribution, invasive history, and unique characteristics, European rabbits are recognizable almost anywhere on our planet. Although they are members of a much larger group of living and extinct mammals [Mammalia, Lagomorpha (rabbits, hares, and pikas)], the group is often characterized by several well-known genera (e.g., Oryct...
Article
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New Zealand’s diplodactylid geckos exhibit high species-level diversity, largely independent of discernible osteological changes. Consequently, systematic affinities of isolated skeletal elements (fossils) are primarily determined by comparisons of size, particularly in the identification of Hoplodactylus duvaucelii, New Zealand’s largest extant ge...
Preprint
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Prehistoric anthropogenically-mediated extinctions have impacted global biodiversity; however effects on herpetofauna are poorly-documented. New Zealand’s Diplodactylidae geckos exhibit high species-level diversity, largely independent of discernible osteological changes (cryptic). Consequently, taxonomic affinities of isolated skeletal elements (f...
Article
Little is known about how the large brains of mammals are accommodated into the dazzling diversity of their skulls. It has been suggested that brain shape is influenced by relative brain size, that it evolves or develops according to extrinsic or intrinsic mechanical constraints, and that its shape can provide insights into its proportions and func...
Preprint
Full-text available
Little is known about how the large brains of mammals are accommodated into the dazzling diversity of their skulls. It has been suggested that brain shape is influenced by relative brain size, that it evolves or develops according to extrinsic or intrinsic mechanical constraints, and that its shape can provide insights into its proportions and func...
Article
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Among vertebrates, placental mammals are particularly variable in the covariance between cranial shape and body size (allometry), with rodents being a major exception. Australian murid rodents allow an assessment of the cause of this anomaly because they radiated on an ecologically diverse continent notably lacking other terrestrial placentals. Her...
Article
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Analyses of morphological disparity have been used to characterize and investigate the evolution of variation in the anatomy, function and ecology of organisms since the 1980s. While a diversity of methods have been employed, it is unclear whether they provide equivalent insights. Here, we review the most commonly used approaches for characterizing...
Article
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Interspecific variation in the craniofacial morphology of kangaroos and wallabies is associated with diet and feeding behaviors. Yet, to how fine a taxonomic scale this relationship might exist is unknown. Using a combination of established morphometric analyses and novel finite element approaches, we test the limits of these associations by examin...
Preprint
Full-text available
Among vertebrates, placental mammals are particularly variable in the covariance between their cranial shapes and body size (allometry), with the notable exception of rodents. Australian murid rodents present an opportunity to assess the cause of this anomaly because they radiated on an ecologically diverse continent unique for lacking other terres...
Article
Full-text available
Urbanization exposes species to novel environments and selection pressures that may change morphological traits within a population. We investigated how the shape and size of crania and mandibles changed over time within a population of brown rats (Rattus norvegicus) living in Manhattan, New York, USA, a highly urbanized environment. We measured 3D...
Article
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Background Morphological diversity among closely related animals can be the result of differing growth patterns. The Australian radiation of agamid lizards (Amphibolurinae) exhibits great ecological and morphological diversity, which they have achieved on a continent-wide scale, in a relatively short period of time (30 million years). Amphibolurine...
Article
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Abstract Background Caecilians (Gymnophiona) are the least speciose extant lissamphibian order, yet living forms capture approximately 250 million years of evolution since their earliest divergences. This long history is reflected in the broad range of skull morphologies exhibited by this largely fossorial, but developmentally diverse, clade. Howev...
Article
Sea snakes (Hydrophiinae) that specialize on burrowing eel prey have repeatedly evolved tiny heads and reduced forebody relative to hindbody girths. Previous research has found that these "microcephalic" forms have higher counts of precaudal vertebrae, and postnatal ontogenetic changes cause their hindbodies to reach greater girths relative to thei...
Article
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Background: Within-species skull shape variation of marsupial mammals is widely considered low and strongly size-dependent (allometric), possibly due to developmental constraints arising from the altricial birth of marsupials. However, species whose skulls are impacted by strong muscular stresses - particularly those produced through mastication o...
Article
The close association between muscle and bone is broadly intuitive; however, details of the covariation between the two has not been comprehensively studied. Without quantitative understanding of how muscle anatomy influences bone shape, it is difficult to draw conclusions of the significance of many morphological traits of the skeleton. In this st...
Article
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A defining character of adaptive radiations is the evolution of a diversity of morphological forms that are associated with the use of different habitats, following the invasion of vacant niches. Island adaptive radiations have been thoroughly investigated but continental scale radiations are more poorly understood. Here, we use 52 species of Austr...
Preprint
Full-text available
Background Within-species skull shape variation of marsupial mammals is widely considered low and strongly size-dependent (allometric), possibly due to developmental constraints arising from the altricial birth of marsupials. However, species whose skulls are impacted by strong muscular stresses – particularly those produced through mastication of...
Article
Morphological variation among the true sea snakes (Hydrophiinae), a clade of fully aquatic elapid snakes, includes an extreme 'microcephalic' ecomorph that has a very small head atop a narrow forebody, while the hind body is much thicker (up to 3 times the forebody girth). Previous research has demonstrated that this morphology has evolved at least...
Article
Full-text available
Grass leaf shape is a strong indicator of their habitat with linear leaves predominating in open areas and ovate leaves distinguishing forest‐associated grasses. This pattern among extant species suggests that ancestral shifts between forest and open habitats may have coincided with changes in leaf shape or size. We tested relationships between hab...
Article
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The past two decades have seen a revolution in digital imaging techniques for capturing gross morphology, offering an unprecedented volume of data for biological research. Despite the rapid increase in scientific publications incorporating those images, the underlying datasets remain largely inaccessible. As the technical barriers to data sharing c...
Article
Full-text available
Analyses of phenotypic integration and modularity seek to quantify levels of covariation among traits to identify their shared functional, developmental and genetic underpinnings ('integration'), which may delineate semi-independent subsets of highly integrated traits ('modules'). Existing studies have focused mainly on mammals or model organisms,...
Article
Snakes exhibit a diverse array of body shapes despite their characteristically simplified morphology. The most extreme shape changes along the precloacal axis are seen in fully aquatic sea snakes (Hydrophiinae): “microcephalic” sea snakes have tiny heads and dramatically reduced forebody girths that can be less than a third of the hindbody girth. T...
Article
Analyses of phenotypic integration and modularity seek to quantify levels of covariation among traits to identify their shared functional, developmental and genetic underpinnings ('integration'), which may delineate semi-independent subsets of highly integrated traits ('modules'). Existing studies have focused mainly on mammals or model organisms,...
Article
Full-text available
Ecomorphology is the association between an organism's morphology and its ecology. Larval anuran amphibians (tadpoles) are classified into distinct ecomorphological guilds based upon morphological features and observations of their ecology. The extent to which guilds comprise distinct morphologies resulting from convergent evolution, the degree of...
Article
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This paper proposes a new methodology to quantify patterns of egg shape variation using geometric morphometrics of three-dimensional landmarks captured on digitally reconstructed eggshells and demonstrates its performance in capturing shape variation at multiple biological levels. This methodology offers unique benefits to complement established li...
Data
Fig. S1. Digital three-dimensional (3D) surface model of a razorbill Alca torda egg using photogrammetry. A total of 145 photographs were taken at multiple angles around the egg. The photographs were processed in Agisoft PhotoScan (v. 1.2.6) to create the 3D model. The specimen (ID number: 2016.R15.Top.LWB) was provided by the Alfred Denny Museum,...
Data
Table S1. Body size, life history and evolutionary origin of four species of bird included in this study. Incubation period is from completion to of clutch to hatching. Sources are Higgins, Peter & Steele, 2001; Higgins & Peter, 2002; Higgins, Peter & Cowling, 2006.
Article
Full-text available
Increasing body size is accompanied by facial elongation across a number of mammalian taxa. This trend forms the basis of a proposed evolutionary rule, cranial evolutionary allometry (CREA). However, facial length has also been widely associated with the varying mechanical resistance of foods. Here, we combine geometric morphometrics and computatio...
Article
Full-text available
Viviparous sea snakes are the most rapidly speciating reptiles known, yet the ecological factors underlying this radiation are poorly understood. Here, we reconstructed dated trees for 75% of sea snake species and quantified body shape (forebody relative to hindbody girth), maximum body length and trophic diversity to examine how dietary specializa...
Article
If Wolff's law is valid, then quantifying the three-dimensional architecture of trabecular bone, specifically 3D principal trabecular orientation (3D-PTO), can reveal joint loading direction among different taxa. This study measured the architecture of trabecular bone in the 3rd metacarpal head of humans and chimpanzees, and then tested their assoc...
Article
Full-text available
Background: Rates of morphological evolution vary across different taxonomic groups, and this has been proposed as one of the main drivers for the great diversity of organisms on Earth. Of the extrinsic factors pertaining to this variation, ecological hypotheses feature prominently in observed differences in phenotypic evolutionary rates across li...